Method of cleaning a deposition chamber and apparatus for depositing a metal on a substrate

ABSTRACT

A method of cleaning a deposition chamber includes applying an RF power to a first region of a deposition chamber where a metal oxide layer is attached. The metal oxide layer in the first region is thicker than the metal oxide layer existing at a second region of the deposition chamber. The RF power increases a plasma sheath potential in the first region to a value that is greater than that of a plasma sheath potential in the second region. An etching gas is introduced into the deposition chamber to remove the metal oxide layer. The metal oxide layer attached to the deposition chamber may be rapidly removed by the in-situ process without opening of the deposition chamber.

CROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims priority under 35 USC § 119 to Korean Patent Application No. 2003-29452, filed on May 9, 2003, the contents of which are herein incorporated by reference in their entirety for all purposes.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present disclosure relates to a method of cleaning a deposition chamber and an apparatus for depositing a metal on a substrate. More particularly, the present disclosure relates to a method of cleaning a metal oxide layer attached to an inner wall of a deposition chamber by an in-situ process without opening of the deposition chamber, and an apparatus for depositing a metal on a substrate.

[0004] 2. Description of the Related Art

[0005] A semiconductor device fabrication process may include a deposition process for forming a layer on a semiconductor substrate. A deposition process is typically performed in a deposition chamber requiring a high vacuum. In a deposition process for forming a metal layer, a metal oxide layer or an oxide layer, gases are introduced into the deposition chamber in which a substrate is disposed. The gases are reacted with each other to form a layer on the substrate.

[0006] A layer is preferably formed only on the substrate during the deposition process. However, an undesired layer is formed on an inner wall and several parts of the deposition chamber as well as on a surface of the substrate. Further, the undesired layer has irregular thickness.

[0007] The undesired layer is continuously accumulated when the deposition process is performed using a single deposition chamber. Particles may detach from the undesired layer and drop on a new substrate disposed in the deposition chamber so that failure of a subsequent process may occur. A cleaning process for removing the undesired layer may be periodically performed for preventing the failure of subsequent processes. For example, an in-situ cleaning process may be performed without opening of the deposition chamber to reduce the number of process steps for fabricating a semiconductor device.

[0008] The layers formed in the deposition chamber vary depending on the types of layers used to fabricate a semiconductor device. For instance, a metal oxide layer, such as an aluminum oxide (Al₂O₃) layer, may be used as an insulating layer having a high dielectric constant. Accordingly, the aluminum oxide layer is deposited on the inner wall and parts of the deposition chamber during formation of the aluminum oxide layer on a substrate. The aluminum oxide layer cannot be etched thoroughly by conventional methods because it has a high hardness and is stable as an anodizing material. Thus, a method of cleaning a deposition chamber to which the aluminum oxide layer is attached is required.

[0009] A conventional etching method is applied to an aluminum oxide layer having a thin thickness that is naturally formed on a pure aluminum layer. In particular, after an aluminum layer is formed on a substrate, a thin aluminum oxide layer having a thickness of about 1 Å to about 100 Å is naturally formed on a surface of the aluminum layer. The thin aluminum oxide layer is formed only on the substrate, while a thicker aluminum oxide layer is formed on an inner wall of the deposition chamber. The aluminum layer and the aluminum oxide layer are etched to form an aluminum wiring.

[0010] The aluminum oxide layer having a thickness of about 1,000 nm to about 100,000 nm is formed on an inner wall of the deposition chamber. Thus, the aluminum oxide layer formed on the inner wall of the deposition chamber may not be sufficiently etched by the conventional method for removing the native aluminum oxide layer. Further, the aluminum oxide layer formed on the inner wall of the deposition chamber is etched at a rapid etching rate compared to native aluminum oxide layer.

[0011] A method and an apparatus for cleaning a deposition chamber are disclosed in U.S. Pat. No. 5,756,400. In the disclosed method, a plasma source gas mixed with a first gas including fluorine and a second gas including chlorine is introduced into the deposition chamber. An undesired aluminum oxide layer attached to an inner wall of the deposition chamber is etched by plasma generated from the reaction of the plasma source gas. However, the first gas including fluorine reacts with aluminum oxide to form a solid aluminum fluoride layer (AlF₃) on the aluminum oxide layer. Accordingly, the above-mentioned method may be inappropriate for removing the aluminum oxide layer.

SUMMARY OF THE INVENTION

[0012] A method of cleaning a deposition chamber according to an embodiment of the invention, in which the deposition chamber includes a first region and a second region, a portion of a metal oxide layer attached to the first region being thicker than a portion of the metal oxide layer attached to the second region, includes applying a radio frequency (RF) power to the first region of the deposition chamber. The RF power increases a plasma sheath potential in the first region to a value that is greater than that of a plasma sheath potential in the second region. An etching gas is introduced into the deposition chamber to remove the metal oxide layer. The etching gas may include boron trichloride (BCl₃), carbon tetrachloride (CCl₄) or boron tribromide (BBr₃).

[0013] An apparatus for depositing metal on a substrate according to an embodiment of the invention includes a deposition chamber having a lower plate on which the substrate is disposed, an upper plate for providing gases into the deposition chamber, and a sidewall that connects the lower plate to the upper plate. Gas supply lines for introducing the gases into the deposition chamber are connected to the upper plate. A plasma generator applies an RF power to the upper plate to generate plasma in the deposition chamber. By-products generated in the deposition chamber are exhausted through exhausting lines. The RF power is about 500 watts to about 4,000 watts.

[0014] An apparatus for depositing metal on a substrate according to another embodiment of the invention includes a deposition chamber having a lower plate on which the substrate is disposed, an upper plate for providing gases, and a sidewall connecting the lower plate to the upper plate. Gas supply lines provide the gases into the deposition chamber through the upper plate. A plasma generator selectively applies a first radio frequency power and a second radio frequency power to the upper plate and the lower plate, respectively, to form plasma in the deposition chamber. Exhaust lines exhaust by-products generated in the deposition chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and other features of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which:

[0016]FIG. 1 is a cross sectional view of an apparatus for depositing metal on a substrate according to an embodiment of the present invention;

[0017]FIG. 2 is a cross sectional view of an apparatus for depositing metal on a substrate according to another embodiment of the present invention;

[0018]FIG. 3 is a cross sectional view of an apparatus for depositing metal on a substrate according to another embodiment of the present invention;

[0019]FIG. 4 is a cross sectional view of an apparatus for depositing metal on a substrate according to another embodiment of the present invention;

[0020]FIG. 5 is a graph showing an etching rate of an aluminum oxide layer relative to RF powers during a cleaning process according to Example 1 of the present invention;

[0021]FIG. 6 is a graph showing an etching rate of an aluminum oxide layer relative to a pressure in a deposition chamber during a cleaning process according to Example 2 of the present invention;

[0022]FIG. 7 is a graph showing an etching uniformity of an aluminum oxide layer relative to a temperature of a lower plate during a cleaning process according to Example 3 of the present invention; and

[0023]FIG. 8 is a graph showing an etching uniformity of an aluminum oxide layer relative to a pressure in a deposition chamber during a cleaning process according to Example 3 of the present invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0024] The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the present invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art. In the drawings, the thickness of layers and regions are exaggerated for clarity. Like reference numerals refer to similar or identical elements throughout. It will be understood that when an element such as a layer, region or substrate is referred to as being “on” or “onto” another element, it can be directly on the other element or intervening elements may also be present.

[0025] Hereinafter, a method of cleaning a deposition chamber and an apparatus for depositing metal on a substrate according to exemplary embodiments of the present invention will be discussed.

[0026]FIG. 1 is a cross sectional view of an apparatus for depositing metal on a substrate according to an embodiment of the present invention.

[0027] Referring to FIG. 1, a deposition chamber 10 includes a lower plate 12 on which a substrate is disposed, an upper plate 20 for providing gases onto the substrate, and a sidewall 30 connecting the lower plate 12 to the upper plate 20. The deposition chamber 10 may have a cylindrical shape.

[0028] A heater 14 for controlling temperature of the substrate is installed beneath the lower plate 12. The lower plate 12 and the sidewall 30 of the deposition chamber 10 may be grounded.

[0029] The upper plate 20 includes a showerhead where a plurality of holes 20 a is formed. The upper plate 20 is composed of a metal so that RF power can be applied to the upper plate 20.

[0030] A first insulator 32 is disposed adjacent to an edge of the upper plate 20 to electrically insulate the upper plate 20 from the sidewall 30. A second insulator 34 is disposed adjacent to an edge of the lower plate 12 to electrically insulate the lower plate 12 from the sidewall 30. Alternatively, the lower plate 12 may be electrically connected to the sidewall 30.

[0031] Gas supply lines 16 are connected to the upper plate 12. The gases, which include a reaction gas or a cleaning gas, flow through the gas supply lines 16 into the deposition chamber 10 through the holes 20 a of the showerhead.

[0032] A plasma generator 24 applies the RF power to the upper plate 20 to excite the gases provided in the deposition chamber 10. The plasma generator 24 includes an RF power source 24 a and an RF power match box 24 b. The RF power match box 24 b is electrically connected to the upper plate 20.

[0033] Exhaust lines 40 are connected to the deposition chamber 10 through the lower plate 12. By-products generated in the deposition chamber 10 are exhausted from the deposition chamber 10 through the exhaust lines 40.

[0034] A method of cleaning a deposition chamber according to an embodiment of the invention will be described below.

[0035] An RF power of about 500 watts to about 4,000 watts is applied to the upper plate 20 of the deposition chamber 10 having an inner wall to which an aluminum oxide layer is attached. The RF power is preferably in a range of about 1,300 watts to about 1,800 watts. Plasma having a high energy is required to increase an etching rate of the aluminum oxide layer attached to the inner wall of the deposition chamber 10.

[0036] The lower plate 12 and the sidewall 30 are grounded. The pressure of the deposition chamber 10 is adjusted to below about 1 Torr. Preferably, the pressure of the deposition chamber 10 is controlled to below about 300 mTorr. The temperature of the deposition chamber 10 is adjusted to a range of about 20° C. to about 1,000° C. A cleaning process may be advantageously performed after a deposition process. Thus, the temperature of the deposition chamber 10 is preferably maintained in a range substantially similar to a temperature of the deposition process. For example, the temperature of the deposition chamber 10 may be in a range of about 300° C. to about 500° C.

[0037] An etching gas is introduced into the deposition chamber 10. Examples of etching gases may include boron trichloride (BCl₃), carbon tetrachloride (CCl₄) or boron tribromide (BBr₃). Carbon tetrachloride gas has a high rapid etching rate relative to the aluminum oxide layer compared to other etching gases. However, carbon tetrachloride gas is inappropriate for the etching gas due to environmental pollution and safety concerns. Thus, boron trichloride gas is preferably used for the etching gas in view of etching rate and environmental preservation.

[0038] Boron trichloride gas is introduced into the deposition chamber 10 at a flow rate of about 10 sccm to about 500 sccm. Preferably, the boron trichloride gas is introduced into the deposition chamber 10 at a rate of about 50 sccm to about 100 sccm.

[0039] An inert gas is introduced into the deposition chamber 10 to carry the etching gas and to reduce by-products generated in the deposition chamber 10. The inert gas is introduced into the deposition chamber 10 at a flow rate of about 10 sccm to about 500 sccm.

[0040] The etching rate of the aluminum oxide layer may vary in accordance with processing conditions. When the RF power increases by about 200 watts, the etching rate also increases by about 100 Å/min. As the pressure of the deposition chamber 10 is increased, the etching rate may also be augmented. The etching rate of the aluminum oxide layer may increase in proportion to the temperature increase of the deposition chamber 10, thereby improving etching uniformity.

[0041] The aluminum oxide layer accumulates on the inner wall of the deposition chamber 10 by repetitive deposition processes. Typically, the aluminum oxide layer is formed using an atomic layer deposition (ALD) process. The ALD process is repeatedly performed through a gas introducing step and a purging step.

[0042] The aluminum oxide layer formed by the deposition process has an irregular thickness. Particularly, the aluminum oxide layer has the largest thickness in a first region of the deposition chamber 10 at which the gas remains for the longest time. Since the time for introducing the gas into the deposition chamber 10 is very short (about 0.1 second), the amount of time the gas remains has an influence on the deposition rate of the aluminum oxide layer. The first region includes a portion of the upper plate 20 for spraying the gas into the deposition chamber 10. Thus, when the ALD process forms the aluminum oxide layer, the aluminum oxide layer having the largest thickness is formed on the upper plate 20.

[0043] Accordingly, the etching rate of the aluminum oxide layer attached to the first region including the upper plate 20 is higher than that of other regions of the deposition chamber 10 so that the aluminum oxide layer attached to the inner wall of the deposition chamber 10 may be completely removed by the in-situ cleaning process.

[0044] According to the present embodiment of the invention, the RF power is applied to the upper plate 20, whereas the sidewall 30 and the lower plate 12 are grounded. The first region of the deposition chamber 10 has a plasma sheath potential that is higher than that of other regions of the deposition chamber 10. Accordingly, the aluminum oxide layer in the first region of deposition chamber 10 is rapidly etched in comparison with the aluminum oxide in other regions of deposition chamber 10.

[0045] In the present embodiment of the invention, the deposition chamber 10 may be cleaned by an in-situ process with an etching rate of above about 500 Å/min. The etching rate of the aluminum oxide layer is about 1,032 Å/minute and the etching uniformity of the aluminum oxide layer is within a range of about 5%. Thus, the aluminum oxide layer attached to the inner wall of the deposition chamber 10 is uniformly and rapidly removed from the deposition chamber 10.

[0046]FIG. 2 is a cross sectional view of an apparatus for depositing a metal on a substrate according to another embodiment of the present invention.

[0047] Referring to FIG. 2, a deposition chamber 10 includes a lower plate 12 on which a substrate is disposed, an upper plate 20 for providing gases onto the substrate, and a sidewall 30 connecting the lower plate 12 to the upper plate 20. A heater 14 is installed beneath the lower plate 12. Alternatively, the heater 14 may be positioned in the lower plate 12. The upper plate 20 has a plurality of holes 20 a.

[0048] A first insulator 32 is positioned between the sidewall 30 and one end portion of the upper plate 12 to electrically insulate the upper plate 20 from the sidewall 30 of the deposition chamber 10. A second insulator 34 is disposed between the sidewall 30 and one end portion of the lower plate 12 to electrically insulate the lower plate 12 from the sidewall 30 of the deposition chamber 10.

[0049] Gas supply lines 16 are connected to the holes 20 a of the upper plate 20. Exhaust lines 40 are connected to the deposition chamber 10 through the lower plate 12.

[0050] A first plasma generator 24 applies a first RF power to the upper plate 20 to excite the gases provided through the gas supply lines 16. The first plasma generator 24 includes a first RF power source 24 a and a first RF power match box 24 b. The first RF power match box 24 b is electrically connected to the upper plate 20.

[0051] A second plasma generator 26 applies a second RF power to the lower plate 12 to excite the gases together with the first RF plasma generator 24. The second plasma generator 26 includes a second RF power source 26 a and a second RF power match box 26 b. The second RF power match box 26 b is electrically connected to the lower plate 12.

[0052]FIG. 3 is a cross sectional view of an apparatus for depositing metal on a substrate according to another embodiment of the present invention.

[0053] Referring to FIG. 3, a deposition chamber 10 includes a lower plate 12 on which a substrate is disposed, an upper plate 20 for providing gases onto the substrate, and a sidewall 30 connecting the lower plate 12 to the upper plate 20. A heater 14 is installed in or beneath the lower plate 12. The upper plate 20 has a plurality of holes 20 a.

[0054] A first insulator 32 is disposed between one end portion of the upper plate and the sidewall 30 to electrically insulate the upper plate 20 from the sidewall 30 of the deposition chamber 10. A second insulator 34 is positioned between one end portion of the lower plate 12 to electrically insulate the lower plate 12 from the sidewall 30. Gas supply lines 16 are connected to the upper plate 20, and exhaust lines 40 are connected to the deposition chamber 10 through the lower plate 12.

[0055] A plasma generator 24 selectively applies a first RF power and a second RF power to the upper plate 20 and the lower plate 12 to excite the gases provided in the deposition chamber 10 through the gas supply lines 16. The plasma generator 24 includes an RF power source 24 a and an RF power match box 24 b. The RF power match box 24 b is electrically connected to the upper plate 20. The RF power match box 24 b is also electrically connected to the lower plate 12 through a connection line 24 c. A switch 24 d selectively connects the RF power match box 24 b to the upper plate 20 or the lower plate 12. Accordingly, the RF power is selectively applied to the upper plate 20 or the lower plate 12 through the single plasma generator 24.

[0056]FIG. 4 is a cross sectional view illustrating an apparatus for depositing metal on a substrate according to another embodiment of the present invention.

[0057] Referring to FIG. 4, a deposition chamber 10 includes a lower plate 12 on which a substrate is disposed, an upper plate 20 for providing gases onto the substrate, and a sidewall 30 that connects the lower plate 12 to the upper plate 20. A heater 14 is installed beneath or in the lower plate 12. The upper plate 20 has a plurality of holes 20 a.

[0058] A first insulator 32 is formed between one end portion of the upper plate 20 and the sidewall 30 to electrically insulate the upper plate 20 from the sidewall 30. A second insulator 34 is disposed between one end portion of the lower plate 12 and the sidewall 30 to electrically insulate the lower plate 12 from the sidewall 30.

[0059] Gas supply lines 16 are connected to the upper plate 20, and exhaust lines 40 are connected to the deposition chamber through the lower plate 12.

[0060] A plasma generator 25 selectively applies a first RF power and a second RF power to the upper plate 20 and the lower plate 12 to excite the gases provided in the deposition chamber 10. The plasma generator 25 includes an RF power source 25 a and an RF power double match box 25 b. The RF power double match box 25 b is electrically connected to the upper plate 20 and the lower plate 12. The RF power double match box 25 b controls two targets so that the first and second RF powers are selectively applied to the upper plate 20 and the lower plate 12.

[0061] A method of cleaning a deposition chamber according to another embodiment of the present invention will be described below.

[0062] The first and second RF powers of about 500 watts to about 4,000 watts are applied to the deposition chamber 10 having the inner wall to which the aluminum oxide layer is attached. The first RF power is applied to the upper plate 20 and the second RF power is applied to the lower plate 12. In at least one embodiment of the invention, the second RF power is applied to the lower plate 12 after the first RF power is applied to the upper plate 20. A high RF power is applied to a first region including the upper plate 20 in the deposition chamber 10 at which the aluminum oxide layer is attached. The aluminum oxide layer in the first region is thicker than the aluminum oxide layer in a second region including the lower plate 12 of the deposition chamber 10. Accordingly, the first RF power is greater than the second RF power.

[0063] The lower plate 12 and the sidewall 30 are grounded. The pressure of the deposition chamber 10 is controlled to below about 1 Torr. Preferably, the pressure of the deposition chamber 10 is controlled to below about 300 mTorr. The temperature of the deposition chamber 10 is adjusted to a range of about 20° C. to about 1,000° C. A cleaning process may be performed after the deposition process. Thus, the temperature of the deposition chamber 10 is substantially identical to a temperature of the deposition process. For example, the temperature of the deposition chamber 10 may be in a range of about 300° C. to about 500° C.

[0064] An etching gas is introduced into the deposition chamber 10 at a flow rate of about 10 sccm to about 500 sccm. Preferably, the etching gas flows at a rate of about 50 sccm to about 100 sccm. Simultaneously, an inert gas is introduced into the deposition chamber 10 at a flow rate of about 10 sccm to about 500 sccm to carry the etching gas and to reduce by-products generated in the deposition chamber 10.

[0065] According to the present embodiment of the invention, the etching rate of the aluminum oxide layer positioned on the lower plate 12 is increased due to the RF power applied to the lower plate 12.

[0066] Experimental results were obtained by performing the processes detailed in the Examples provided below.

EXAMPLE 1

[0067] An aluminum oxide layer was attached to an inner wall of a deposition chamber after performing a deposition process. A boron trichloride (BCl₃) gas was introduced into the deposition chamber at a flow rate of about 70 sccm. An argon (Ar) gas was introduced into the deposition chamber at a flow rate of about 30 sccm. A lower plate of the deposition chamber was heated to a temperature of about 42° C. A pressure of the deposition chamber was set to about 183 mTorr. RF power of about 1,000 watts to about 1,500 watts was applied to an upper plate of the deposition chamber to etch the aluminum oxide layer attached thereto.

[0068] A graph of the power versus the etching rate of the aluminum oxide layer is shown in FIG. 5. In FIG. 5, the X-axis represents the RF power and the Y-axis represents the etching rate. The etching rate was measured at a portion of the upper plate.

[0069] Referring to FIG. 5, the etching rate increased in proportion to augmentation of the RF power. When the RF power increased from about 1,000 watts to about 1,200 watts, for example, the etching rate increased from about 500 Å/minute to about 600 Å/minute.

EXAMPLE 2

[0070] An aluminum oxide layer was attached to an inner wall of a deposition chamber after performing a deposition process. A boron trichloride (BCl₃) gas was introduced into the deposition chamber at a flow rate of about 70 sccm. An argon (Ar) gas was introduced into the deposition chamber at a flow rate of about 30 sccm. A lower plate of the deposition chamber was heated to a temperature of about 42° C. The pressure of the deposition chamber were set from about 153 mTorr to about 183 mTorr. RF power of about 1,500 watts was applied to an upper plate of the deposition chamber to etch the aluminum oxide layer.

[0071] A graph of the pressure versus the etching rate of the aluminum oxide layer is shown in FIG. 6. In FIG. 6, the X-axis represents the pressure of the deposition chamber and the Y-axis represents the etching rate. The etching rate was measured at a portion of the upper plate.

[0072] Referring to FIG. 6, the etching rate decreased in proportion to a rise of the pressure. When the pressure increased from about 160 mTorr to about 170 watts, for example, the etching rate decreased from about 900 Å/min. to about 800 Å/min.

EXAMPLE 3

[0073] An aluminum oxide layer was attached to an inner wall of a deposition chamber after performing a deposition process. A boron trichloride (BCl₃) gas was introduced into the deposition chamber at a flow rate of about 70 sccm. An argon (Ar) gas was introduced into the deposition chamber at a flow rate of about 30 sccm. A lower plate of the deposition chamber was heated to a temperature of about 42° C. to about 300° C. The pressure of the deposition chamber was set to about 153 mTorr. RF power of about 1,500 watts was applied to an upper plate of the deposition chamber to etch the aluminum oxide layer attached thereto.

[0074] A graph of temperature of the lower plate versus etching uniformity of the aluminum oxide layer is shown in FIG. 7. In FIG. 7, the X-axis represents the temperature of the lower plate and the Y-axis represents the etching uniformity. The etching uniformity under pressure of about 153 mTorr is indicated as a line 100 and the etching uniformity under pressure of about 183 mTorr is indicated as a line 102.

[0075] In addition, a graph of pressure versus etching uniformity of the aluminum oxide layer is shown in FIG. 8. In FIG. 8, the X-axis represents the pressure of the deposition chamber and the Y-axis represents the etching rate. The etching uniformity at a temperature of about 42° C. is indicated as a line 104 and the etching uniformity at a temperature of about 300° C. is indicated as a line 106. The etching uniformity of the aluminum oxide layer was measured at a portion of the upper plate.

[0076] A thickness of the etched aluminum oxide layer increases as the etching uniformity is lowered. The etching uniformity of the aluminum oxide layer is obtained by the following equation:

Etching uniformity=[(x−y)/2z]×100

[0077] where, x indicates a maximum thickness of the aluminum oxide layer, y indicates a minimum thickness of the aluminum oxide layer, and z represents an average thickness of the aluminum oxide layer.

[0078] Referring to FIGS. 7 and 8, the etching uniformity was improved in proportion to an increase of the temperature of the lower plate. The etching uniformity of the aluminum oxide layer varied in a wide range at a low temperature of the lower plate in comparison with the etching uniformity at a high temperature of the lower plate. The pressure of the deposition chamber should be determined considering variation of the etching uniformity of the aluminum oxide layer in accordance with the temperature of the lower plate.

[0079] According to various exemplary embodiments of the present invention, the aluminum oxide layer attached to the deposition chamber may be removed by an in-situ process without opening of the deposition chamber. In addition, the aluminum oxide layer may be rapidly removed so that time required for the cleaning process may be reduced.

[0080] Although exemplary embodiments of the present invention have been described, it should be understood that the present invention is not limited to these exemplary embodiments but various changes and modifications can be made by one of ordinary skilled in the art within the spirit and scope of the present invention as hereinafter claimed. 

What is claimed is:
 1. A method of cleaning a deposition chamber, the deposition chamber comprising a first region and a second region, a portion of a metal oxide layer attached to the first region being thicker than a portion of the metal oxide layer attached to the second region, the method comprising: applying a first radio frequency power to the first region of the deposition chamber to increase a plasma sheath potential in the first region to a value that is greater than that of a plasma sheath potential in the second region; and introducing an etching gas into the deposition chamber to remove the metal oxide layer.
 2. The method of claim 1, wherein the first radio frequency power is in a range of about 500 watts to about 4,000 watts.
 3. The method of claim 1, wherein the deposition chamber includes an upper plate, a lower plate and a sidewall connecting the upper plate to the lower plate, and the first radio frequency power is applied to the upper plate.
 4. The method of claim 3, wherein the lower plate and the sidewall are grounded.
 5. The method of claim 3, wherein the sidewall is grounded, and a second RF power is applied to the lower plate.
 6. The method of claim 5, wherein applying the second radio frequency power to the lower plate is performed after applying the first radio frequency power to the upper plate.
 7. The method of claim 5, wherein the first RF power is greater than the second RF power.
 8. The method of claim 1, wherein the pressure of the deposition chamber is below about 1 Torr.
 9. The method of claim 1, wherein temperature of the deposition chamber is about 20° C. to about 1,000° C.
 10. The method of claim 1, further comprising introducing an inert gas into the deposition chamber.
 11. The method of claim 10, wherein the inert gas is introduced into the deposition chamber at a flow rate of about 10 sccm to about 500 sccm.
 12. The method of claim 1, wherein the deposition chamber is an atomic layer deposition (ALD) chamber.
 13. The method of claim 1, wherein the metal oxide layer is an aluminum oxide layer.
 14. The method of claim 13, wherein the etching gas comprises boron trichloride (BCl₃), carbon tetrachloride (CCl₄) or boron tribromide (BBr₃).
 15. The method of claim 14, wherein the boron trichloride gas is introduced into the deposition chamber at a flow rate of about 10 sccm to about 500 sccm.
 16. An apparatus for depositing a metal on a substrate comprising: a deposition chamber including a lower plate on which the substrate is disposed, an upper plate for providing gases, and a sidewall connecting the lower plate to the upper plate; gas supply lines for providing the gases into the deposition chamber through the upper plate, the gases comprising a depositing gas or a cleaning gas; a first plasma generator for applying a first radio frequency power to the upper plate to form a plasma in the deposition chamber; and exhaust lines for exhausting by-products generated in the deposition chamber.
 17. The apparatus of claim 16, further comprising a second plasma generator for applying a second radio frequency power to the lower plate.
 18. The apparatus of claim 16, wherein the exhaust lines are connected to the deposition chamber through the lower plate.
 19. An apparatus for depositing a metal on a substrate comprising: a deposition chamber comprising a lower plate on which the substrate is disposed, an upper plate for providing gases, and a sidewall connecting the lower plate to the upper plate; gas supply lines for providing the gases into the deposition chamber through the upper plate, the gases comprising a depositing gas or a cleaning gas; a plasma generator that selectively applies a first radio frequency power and a second radio frequency power to the upper plate and the lower plate, respectively, to form a plasma in the deposition chamber; and exhaust lines that exhaust by-products generated in the deposition chamber.
 20. The apparatus of claim 19, further comprising a switch that selectively connects the plasma generator to the upper plate and the lower plate.
 21. The apparatus of claim 19, wherein the exhaust lines are connected to the deposition chamber through the lower plate.
 22. The apparatus of claim 19, wherein the plasma generator comprises a power double matchbox that is electrically connected to the lower plate and the upper plate.
 23. The apparatus of claim 20, wherein the plasma generator comprises a power matchbox that is electrically connected to the lower plate and the upper plate by the switch. 